Ecology and physiology of establishment of eucalypt seedlings from seed: A review

Summary

This paper provides a comprehensive review of the ecological and physiological factors affecting the establishment of eucalypts from seed, with particular reference to native forests and woodlands in Australia. Water, temperature, light in some cases, seed harvesting, pathogens, allelopathy, overstorey density and seedbed all have the potential to affect germination and emergence of eucalypts, but probably the most generally important factors are seed harvesting, water and seedbed condition. Mortality of eucalypt seedlings has been attributed to water deficits, high soil-surface temperatures, pathogenic fungi, low light intensity, frost, freezing temperatures, snow, fire, grazing and high seedling density. Mortality is usually greater beneath an overstorey and on undisturbed seedbeds, and may be reduced by application of fertilisers. Probably the most widespread causes of mortality are water deficits, especially in the drier areas, pathogens and the unsuitable conditions of an undisturbed seedbed. Water, temperature, light, allelopathy, grazing, competition from overstorey and understorey vegetation, seedbed conditions, mycorrhizal roots and application of fertilisers all affect growth of eucalypt seedlings. The most generally important factors are water, temperature and light, all of which can be influenced by the density of overstorey and understorey vegetation; and nutrients. Areas of further research are recommended.